YTD439
ISTU
ISDN BRI controller for Terminal Equipment with built-in DSU
❑
Abstract
YTD439 is a LSI that integrates in a single chip all the communication functions that are
necessary for constructing an ISDN terminal with a built-in DSU. The functions of both the DSU
(U reference point) and terminal (S/T reference point) are packed into the 100-pin SQFP chip
allowing miniaturization of the terminal equipment.
YTD439 has a built-in TD switch function that is necessary for controlling the connection of the
B-channel data. By connecting an external CPU, memory, and CODEC, a terminal with a built-in
DSU can be configured. In addition, YTD439 has a function that reduces the power consumption
by stopping the functions of unused blocks. This is effective for battery-driven terminals.
❍
Features
DSU block
• Conforms to TTC Standards JT-I430 and JT-G961.
• LT (line termination) function and CT (circuit termination) function.
• DSU can be disconnected.
S/T reference point driver/receiver block
• Transition to the sleep state possible by setting an I/O register.
CPU interface block
• 8-bit or 16-bit data bus selectable.
• I/O access through registers.
YTD439 CATALOG
CATALOG No.:4TD439A2
2001.1
Layer 1 control block
• Frame assembling and disassembling function.
• I430 TTL output pin
Layer 2 control block
• Built-in LAPD protocol (supports four links).
• Call control and D-channel packet function.
Layer 3 interface block
• Message exchange through I/O access (large 1088-byte FIFO).
B channel HDLC controller
• Supports CRC-CCITT and CRC-32.
• 128k/64k/56k rate adaption
B channel transparent
• Supports PIAFS 64k/32k.
• Flexible rate adaption function.
B channel DATA FIFO
• Transmission and reception: 128-byte FIFO
×
2 channels.
TD switch
• Switch circuit for 8 channels of B channel data.
• 512 k to 2,048 kHz PCM highway.
Others
• Terminal block can be disconnected. Power can be cut off.
• Terminal block sleep mode.
• Power supply to the analog block: +5 V.
Power supply to the digital block: +5 V or 3.3 V.
• 5 V tolerant I/O pin
• 100-pin SQFP.
❍
Applications
• Terminal adapter
• Remote router
• ISDN telephone
• ISDN home telephone
• ISDN Facsimile
-2-
❍
Functional Comparison of YAMAHA ISDN LSIs
Function
DSU Function
Layer 1
Layer 2
TTC Standard
TTC Standard
TTC Standard
JT-G961
JT-I430
JT-Q920
JT-Q921
1993 edition
YTD421
YTD428
1997 edition
1993 edition
1993 edition
1993 edition
1997 edition
1993 edition
1998 edition
YTD423
YTD436
YTD439
1997 edition
1997 edition
1993 edition
1998 edition
ETSI
ETS 300 012, ETS 300 125
North American Switches
National ISDN-1/2, AT&T 5ESS,
Nortel DMS-100
S/T Ref. Point Analog Driver/Receiver
Circuit switching
Maximum D
Channel Links Dch Packet Switching
(Teleaction communication)
D Channel Layer 3 Data Transfer Method
HDLC Controller for B Channel Data
√
√
√
√
External
[YTD421]
2
2
√
√
√
2
2
(2)
or
√
2
2
(2)
I/O Transfer
DMA Transfer DMA Transfer
or
I/O Transfer
I/O Transfer
External
DMA Transfer
or
√
DMA Transfer
or
√
I/O Transfer
B Channel Data Transfer Method
I/O Transfer
B Channel Internal Clock Mode (kHz)
B Channel External Clock Mode
TD Switch
Clock Output Function for CPU
Signal Output Function for Testing
+5
Power Supply (V)
5-V Tolerant I/O pin
Package
Note 1:
DMA transfer: Request function only
I/O transfer: 4-byte FIFO
Note 2:
Digital power supply only
or
I/O Transfer
(Note
1)
32, 56, 64
32, 56, 64
√
√
√
√
√
√
+5
+5
√
√
+5
or
√
√
+5
or
+3.3 (Note
2)
+3.3 (Note
2)
+3.3 (Note
2)
√
20-pin SSOP 100-pin SQFP 100-pin SQFP 100-pin SQFP 100-pin SQFP
-3-
❑
Block Diagram
❍
User-Network Interface Block Diagram
YTD439 is best-suited for applications in terminal equipment with built-in DSU (TA, TE1)
such as terminal adapters and remote routers with built-in DSUs.
YTD439 contains a DSU function, which is necessary between the ISDN switch and the user-
network interface, and layer 1 and layer 2 functions, which are required of ISDN system
equipment. By adding minimal peripheral parts such as microprocessor and CODEC, terminal
equipment can be optimally configured.
R
TE2
S/T
TE1
S
T
TA with
built-in DSU
U
ISDN
Network
TE1
(ISDN terminal)
R
S
NT2
(PBX, etc.)
NT1
(DSU)
TE2
(Non-ISDN
terminal)
TA
(Terminal adapter)
S/T
TE1
R
YTD439
S/T
U
YTD436 or
YTD423 + YTD421
TE1
User's premises
TE2
TA with
built-in DSU
YTD428 (DSU)
-4-
B channel PCM highway I/F (CODEC, etc)
(512 k to 2,048 kHz )
Terminal
block
Internal bus
B channel connection section
TD switch (8ch)
Control
I/O register
❍
Internal Block Diagram
64k
×
2
HDLC
controller
Rate adaption
block
B channel
data
FIFO
(128 byte
×
2)
B1/B2
channel
Transparent
PIAFS
Layer 1
control
block
B channel data control block (CH-A)
B channel data control block (CH-B)
CPU I/F
Programmable I/O
S/T ref.
point
16k
D channel
Layer 2 control
block
(LAPD)
Layer 3 I/F block
FIFO
(1088 byte)
S/T ref.
point
driver/
receiver
block
Circuit
termination
block
T ref.
point
connection
control
block
Line
termination
block
DSU block
U ref.
point I/F
U ref. point
Clock
generator
15.36 MHz
-5-
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